426 



THE POPULAR SCIENCE MONTHLY. 



variety are susceptible of decided improve- 

 ment by early and persistent training of 

 the individual. In cases of the other kind, 

 however, which are generally hereditary, he 

 believes that amelioration can be brought 

 about, if at all, only by a course of educa- 

 tion applied to successive generations. The 

 author finds fault with the general neglect 

 of the subject in our schools, and also with 

 the methods practiced in the few instances 

 where such training has been attempted. 

 In the Washington schools the practice is 

 to use a chart on which the various colors 

 are painted. These colors soon become so 

 faded and dim as to no longer represent 

 what was originally intended ; and, even 

 with this imperfect chart, no systematic 

 instruction is given in the comparison of 

 the colors. The first requisite, in Dr. Bur- 

 nett's opinion, for succeessfuUy teaching 

 color to children is, that the method shall 

 be simple and easy. The study should also 

 be made interesting, so that the children 

 will pursue it more as a diversion than a 

 task. Each child should be taught separate- 

 ly, but the instruction may be carried on in 

 such a manner that the other children can 

 participate. As the main object is to en- 

 able the child to discriminate between the 

 various colors, the comparison of one color 

 with another will be the principal part of 

 the work. Bat the pupil should at the 

 same time be taught the names of the 

 colors and shades, so as to be able to con- 

 vey the impressions he has received in 

 definite language. To carry out these in- 

 dications in a simple and effective way, 

 there are required — first, a set of sample 

 colors with which comparisons are to be 

 made; and, second, a collection of colors 

 from which the pupil may choose such as 

 are to be compared with the sample. Tor 

 the former. Dr. Burnett recommends the 

 following : " Take a half-sheet of white 

 perforated cardboard (42 x 26 cm.) with 

 the largest size perforations, and work into 

 it, with Berlin wool, bars 18 cm. in length 

 and 35 mm. in width, of each of the follow- 

 ing colors : red, green, and blue, with a dis- 

 tance of 1'5 cm. between them. These 

 should be as pure as possible, and represent 

 the three primary colors. Then, beginning 

 3 cm. below, work in at the same distances 

 apart each of the following colors of me- 

 dium shade and as pure as can be got: 



purple, orange, yellow, pink, brown, and 

 gray. A single skein of Berlin wool is 

 generally enough to work a bar of the re- 

 quired length and width, which is sufficient- 

 ly large to be seen distinctly across any 

 ordinary schoolroom by a normal eye. This 

 card is to be placed on a white background 

 on the wall in sight of all the pupils." In 

 the process of instruction the pupils are 

 fix'st familiarized with this card, and with 

 the names of the colors represented on it, 

 and, when able to designate each of these 

 correctly, the teacher will explain what is 

 meant by a " shade," and, taking a package 

 of Berlin wools containing all the shades of 

 the nine colors on the card, will pick out 

 and exhibit to the class all the shades of 

 one of the colors. After this, the shades 

 are tiioroughly mixed with the other colors 

 in the pile, and the pupils are then called 

 upon to do the choosing, arranging them in 

 regular order from darkest to lightest. The 

 same process is to be repeated with each 

 of the colors on the card. 



Popalation of Africa. — Accurate statis- 

 tics of the population of Africa, and espe- 

 cially of the interior portions of the conti- 

 nent, are of course not yet obtainable, and 

 it will probably be many years before sev- 

 eral of the populous districts now known 

 will be sufficiently accessible for a thorough 

 census ; but much important information 

 has been gathered about the distribution of 

 the inhabitants and the density of the popu- 

 lation in the different parts of the country. 

 In the region of the great lakes, for exam- 

 ple, there are countries as thickly peopled 

 as many of the states of Europe — relatively 

 small areas which, according to Stanley, 

 possess millions of inhabitants. Behna 

 states that the negro regions are by far the 

 most populous, while the desert parts repre- 

 sent the other extreme. M. A. Rabaud, in 

 a paper published in the " Bulletin of the 

 Marseilles Geographical Society," gives the 

 following as the population of the different 

 subdivisions of the continent : In the Sou- 

 dan, the population is estimated at 80,000,- 

 000, or about fifty-three per square mile ; 

 the town of Bida, on the Niger, contains 

 80,000 inhabitants. The population of 

 East Africa is estimated at 30,000,000, and 

 that of Equatorial Africa at about 40,000,- 

 000. One of the latest authorities divides 



